When, during the operation of an automobile, rapid acceleration or deceleration is caused by quickly operating the accelerator pedal, the engine torque sharply changes and the driving system including the drive shaft is twisted, which may generate back-and-forth vibration on the vehicle. This type of vehicle's back-and-forth vibration is called “jerking” and lowers drivability so it is a phenomenon that must be prevented. To essentially prevent the jerking, it suffices to set a small amount of change in the engine torque generated during acceleration and deceleration so as to control the twist of the driving system. When the amount of engine torque is just lessened, however, the accelerator response during acceleration or deceleration is lowered. Accordingly, a technology that satisfies both suppression of the vehicle's back-and-forth vibration and acceleration and deceleration response is desired.
Some technologies that satisfy the demands described above are disclosed. A first known technology is, for example, a technology described in Japanese Patent Laid-open No. Hei 3 (1991)-271537 (Patent Document 1). In Patent Document 1, a transmission function Gp(s) between an accelerator opening and a driving torque and another transmission function Gm(s) between a target acceleration opening and the driving torque are obtained and used to calculate a phase compensation value W(s) [=Gm(s)/Gp(s)]; W(s) is then used to control a throttle actuator (inverse filter control)
A second known technology is, for example, a technology described in Japanese Patent Laid-open No. 2001-355476 (Patent Document 2). In Patent Document 2, when there is drive train vibration, the drive torque is reduced until the vibration is eliminated, and the torque value generated during the vibration is recorded. When a torque generated during a next acceleration or later exceeds the recorded torque value, the increase in the torque is restricted.